Nitrostarch explosive



a carton.

CHARLES E. WALLER, OF ALLENTOWN, PENNSYLVANIA, ASSXGNOR T INDEPENDENE NON-FREEZING POWDER COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

NITROSTARCH EXPLOSXVE.

No Drawing.

"1'0 all w/wm it may (one 01%.,

,Be it known that I, CnAuLns E. \VaLLnu, a c tizen of thei'Umted States, and a resident of itllcntown, Lehigh county, Pennsylvania,

- of suitable oils added thereto to give consistency and to render waterproof. These explosives have been of the class known as high explosives containing comparatively high percentages of nitro-starch and having as their characteristic feature when exploded a. relatively quick action[ For some blasting operations it is desirable to use explo- Isivcs of slow action.that is, having more of a heaving force than ashattering efiect. The explosives which have heretofore been I used for this class of work are black powder and the so-called low powders containing small percentages of nitro-glyccrin. It is the object of this invention to provide a similar slow acting nitro-starch explosive.

The difiiculty which has heretofore been experienced by experimenters in'search of such a nitro-starch explosive has been that these explosives in the ordinary form have proven" too insensitive to detonation when the percentage of nitro-starch has been recluced to. the point where the action of the explosive is as slow as is necessary to meet the requirements of the class. For instance, mixtures, containing from ten per cent. (10%) to fifteen per cent. (15%) of nitrostarch together with suitable-percentages of .an oxygen bearer, such as'nitrate of soda and of combustible matter such as sulfur and charcoal, fail to explode with an ordinary detona-ting ca-p even when confined under such conditions as exist in practice. In fact, with nitro-starch as high as twenty-five per cent. (25%), mixed with certain desired pro- 7 portion of oxygen carrier and combustible,

the powder in the ordinary form of nitrostarch powders cannot be detonated under all conditions met in ordinary ractice. I have discovered that by granu sting such mixtures, however, in accordance with the method which I shaii describe, the resultant granular explosives will explode under the Specification of Letters Patent.

-monly employed for such purpose.

Patented a "no a, rats.

Application filed January 22, 1915.v Serial No. 3,783.

conditions which exist in blasting operations with as low a proportion of nitro starch as hve per cent. (5%), and various mixtures containing from five per cent.

(5%) to twenty-five per cent. (25%) nitrostarch. which before could not. be used in practice. become. in the form in which. .I produce them, entirely practical. Further more, the rate of detonation of-such explosives is slow and suitable for such biast ing operations as mentioned above.

I describe my method of-producing the granular nitrostarch explosives as follows:

As an oxygen carrier i employnitrate of soda, or any equivalent oxygen carrier comcombustible matter ii zse charcoal or an similar combustible \TdUbOIHICQUHS nnrterial and sulfur. Nitro-sta-rch is used as the explosive base. Any suitable antacid may be employed, and "it desirable a. small pore/entage of a. suitable waterproofing oil may be added. As a. binder I use starch paste.

In preparing the explosive I first thoroughly mix. by any suitable means, the various ingredients other than the nitro-starch. I then add and thoroughly mix in the nitrostarch. To the mass thus obtained 1' add liquid starch paste prepared by heating one part of corn starch with twenty-five parts of Water. The explosive mixture and the starch paste are then thoroughly mixed and incorporated. The entire mass is then rubbed through a screen, preferably of four to six mesh, on to trays, and dried. The dried mass is then readily broken up into the desired granular form. This method is to be sharply"distinguished from that in which a mass is compressed and grained. in the manufacture of gun-powder. Compression Won-id prevent detonation and my prod not must be uncompressed;

In "carryn'ig out my process I have found that good results can be obtained by {Kidfllfi twenty-six (26) parts, by weight. of they For uct should not contain more than four per ,freeze as do low powders containing small percentages of intro-glycerin. The character of their action on explosion 18 slow and 'much more suitable to the work for which they are intended than are any of the granular chlorate explosives. The matter of first importance is that they can be detonated under practical service conditions with ordinary detonating caps, while the same mixture in the ordinary form could not be so used.

An example of one formula which I have used with good results is as follows:

Nitro-starch- 10 Sodium nitrate 73 Sulfur 7.5 Charcoal 7.5 Calcium carbonate 1 Dried starch paste 1 I do not confine myself to the above proportions, however, these may be varied with in certain limits and still give satisfactory results in varying degrees. The percentages which I believe may be used to obtain the {esults which I have described are as folows:

Nitro-starch From 5% to 25% Sodium nitrate to 85% Sulfur 2% to 10% Charcoal 2% to 10% Calcium carbonate.-. 1% to 3% Dried starch paste 1% to 3% N or do I confine myself to the specific oxygen bearer, combustible material or antacid named above. For instance, instead of sodium nitrate, potassium nitrate or barium nitrate or any other well known oxygen carriers may be used. In the place of charcoal there may be used lamp black, iinely ground coal or any suitable combustible carbonaceous material. The calcium carbonate may be replaced with sodium iii-carbonate or any other well known antacid.

I claim:

1. A granular nitro-starch explosive whose sole detonating ingredient is intro-starch; the percentage of nitro-starch present being such that the explosive is incapable of detonation in-non-granular bulk form under ordinary conditions.

2. A granular nitro-starch explosive containing nitrostarch as the sole detonating ingredient; said nitro-starch being present to the extent of approximately live to twenty-five per cent. by weight of the whole explosive.

3. A granular, uncompressed, detonating explosive containing nitro-starch, and in cludmg a binder of agglutlmzlng material;

said intro-starch being present to the extent of approximately five to twenty-five per cent. by weight ,of the whole explosive.

4. A granular, uncompressed, detonating explosive containing five to twenty-five per cent. by weight of nitro-starch, and including a binder of starch paste which, when dry,approximates one to three per cent. by weight of the entire mixture.

5. A granular, uncompressed, detonating explosive containing five to twenty-fiveper cent. by weight of nitro-starch, an oxygen carrier, combustible carbonaceous material, and a starchy binder approximating one to three per cent. by weight of the entire mixture.

, 6. A granular, uncompressed, detonating explosive containing five to twenty-five per cent. by weight of nitro-starch, fifty to eighty-five per cent. of sodium nitrate, two

to ten per cent. of sulfur, two to ten per cent.

of charcoal, one to three per centof calcium carbonate, and a binder of starch approxi mately one to three per cent. by weight of the entire mixture.

In testimony whereof, I have signed my name to this specification, in the presenceof two subscribing witnesses.

' CHARLES E. WALLER.

Witnesses:

CHARLES H. I-lowsoN, Jos. H. KLEIN. 

